1. Field of the Invention
Modern production methods, easy-care kitchen, bathroom and cellar fittings, plastic-veneered furniture, the equipping of households to an increasing extent with freezers, refrigerators, washing machines and dishwashers, i.e. appliances with enamelled or plastic-coated metal walls of large surface area, ensure a continuing demand for liquid multipurpose cleaners for use in the home. In industry also, the importance of using liquid multipurpose cleaners shows no sign of diminishing. The main demand is still for easy and problem-free use. The cleaners are generally marketed in the form of preferably water-based concentrates. They may be applied in diluted or undiluted form to a moist absorbent cloth of any quality or to a sponge with which hard surfaces of metal, painted wood, plastic, ceramic products, such as porcelain, tiles and the like, can then be wiped and thus freed from dust, greasy soil and stains. It is desirable that the cleaner used should not leave behind any marks or streaks after this surface treatment and that there should be no need for aftertreatment with a damp cloth soaked with clear water.
2. Discussion of Related Art
Numerous multipurpose liquid cleaners are already known both from the market and from the literature. In addition, it is also known from the patent literature that various polymers can be added to such cleaners to enhance their cleaning performance.
Thus, AT-PS 278 216 describes liquid cleaners which may contain water-soluble high molecular weight substances as soil suspending agents. Water-soluble salts of polyacrylic acid inter alia are mentioned as examples.
German patent applications 28 40 463 and 28 40 464 describe the use of high molecular weight polyethylene glycols while German patent application 29 13 049 describes the use of inter alia polyvinyl alcohols, polyvinyl pyrrolidones and polyacrylamides as detergency boosters.
According to GB-PS 1,073,947, polyacrylamides inter alia improve the soil suspending power of liquid cleaners for hard and poorly accessible surfaces.
German patent application 22 20 540 describes polymers of aromatic monovinyl monomers with unsaturated dicarboxylic acids while European patent application 66 342 describes the same class of compounds, but in partly esterified form, for improving the appearance of the cleaned surfaces and for avoiding the misting of glass by steam.
British patent application 2,104,091 describes liquid cleaners which, in addition to typical anionic, nonionic, cationic or amphoteric surfactants, contain an addition of an amphoteric polymer compound prepared by polymerization of a cationic vinyl monomer with an anionic vinyl monomer. This addition, which is used in smaller quantities by comparison with the surfactant, is said to improve cleaning power.
Finally, DE 37 20 262 describes liquid cleaners for hard surfaces which contain a detergency-boosting mixture of polyacrylamides and highly polyethoxylated monofunctional or polyfunctional alkanols containing 12 to 22 carbon atoms in the molecule.
For the most part, these polymers, some of which have been known for a long time, have not acquired any appreciable significance as additives to domestic cleaners used in large quantities. Some of the disadvantages of these known polymers include, for example, their inadequate solubility in the cleaner, their excessive thickening effect and the formation of residues, i.e. streaks or films, in the practical application of the cleaners when the polymers are present in the quantities required to boost detergency. However, the complicated production of these known polymers and their inadequate stability in storage were also obstacles to their problem-free use in practice.